USB: dwc2: write HCINT with INTMASK applied

commit 0583bc776ca5b5a3f5752869fc31cf7322df2b35 upstream.

dwc2_hc_n_intr() writes back INTMASK as read but evaluates it
with intmask applied. In stress testing this causes spurious
interrupts like this:

[Mon Aug 14 10:51:07 2023] dwc2 3f980000.usb: dwc2_hc_chhltd_intr_dma: Channel 7 - ChHltd set, but reason is unknown
[Mon Aug 14 10:51:07 2023] dwc2 3f980000.usb: hcint 0x00000002, intsts 0x04600001
[Mon Aug 14 10:51:08 2023] dwc2 3f980000.usb: dwc2_hc_chhltd_intr_dma: Channel 0 - ChHltd set, but reason is unknown
[Mon Aug 14 10:51:08 2023] dwc2 3f980000.usb: hcint 0x00000002, intsts 0x04600001
[Mon Aug 14 10:51:08 2023] dwc2 3f980000.usb: dwc2_hc_chhltd_intr_dma: Channel 4 - ChHltd set, but reason is unknown
[Mon Aug 14 10:51:08 2023] dwc2 3f980000.usb: hcint 0x00000002, intsts 0x04600001
[Mon Aug 14 10:51:08 2023] dwc2 3f980000.usb: dwc2_update_urb_state_abn(): trimming xfer length

Applying INTMASK prevents this. The issue exists in all versions of the
driver.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Tested-by: Ivan Ivanov <ivan.ivanov@suse.com>
Tested-by: Andrea della Porta <andrea.porta@suse.com>
Link: https://lore.kernel.org/r/20231115144514.15248-1-oneukum@suse.com
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc2/hcd_intr.c b/drivers/usb/dwc2/hcd_intr.c
index 0144ca8..5c7538d 100644 (file)
--- a/drivers/usb/dwc2/hcd_intr.c
+++ b/drivers/usb/dwc2/hcd_intr.c
@@ -2015,15 +2015,17 @@ static void dwc2_hc_n_intr(struct dwc2_hsotg *hsotg, int chnum)
 {
        struct dwc2_qtd *qtd;
        struct dwc2_host_chan *chan;
-       u32 hcint, hcintmsk;
+       u32 hcint, hcintraw, hcintmsk;
 
        chan = hsotg->hc_ptr_array[chnum];
 
-       hcint = dwc2_readl(hsotg, HCINT(chnum));
+       hcintraw = dwc2_readl(hsotg, HCINT(chnum));
        hcintmsk = dwc2_readl(hsotg, HCINTMSK(chnum));
+       hcint = hcintraw & hcintmsk;
+       dwc2_writel(hsotg, hcint, HCINT(chnum));
+
        if (!chan) {
                dev_err(hsotg->dev, "## hc_ptr_array for channel is NULL ##\n");
-               dwc2_writel(hsotg, hcint, HCINT(chnum));
                return;
        }
 
@@ -2032,11 +2034,9 @@ static void dwc2_hc_n_intr(struct dwc2_hsotg *hsotg, int chnum)
                         chnum);
                dev_vdbg(hsotg->dev,
                         "  hcint 0x%08x, hcintmsk 0x%08x, hcint&hcintmsk 0x%08x\n",
-                        hcint, hcintmsk, hcint & hcintmsk);
+                        hcintraw, hcintmsk, hcint);
        }
 
-       dwc2_writel(hsotg, hcint, HCINT(chnum));
-
        /*
         * If we got an interrupt after someone called
         * dwc2_hcd_endpoint_disable() we don't want to crash below
@@ -2046,8 +2046,7 @@ static void dwc2_hc_n_intr(struct dwc2_hsotg *hsotg, int chnum)
                return;
        }
 
-       chan->hcint = hcint;
-       hcint &= hcintmsk;
+       chan->hcint = hcintraw;
 
        /*
         * If the channel was halted due to a dequeue, the qtd list might